A STRAWBERRY CROP CAN ACHIEVE STANDARD YIELDS WITHOUT FERTILIZATION IN THE ESTABLISHMENT YEAR

Abstract

A trial was conducted to evaluate the effect of the exclusion of fertilizers during the first year on the production of strawberry 'Camarosa' during two harvest seasons. The experiment was established in January 2003 at the experimental station of INIA, Chillan, Chile (36°32'S; 71°55'W) in a volcanic soil with 6.8% of organic matter which was increased to 7.8% after soil fumigation with methyl bromide previous planting of the strawberries. The field experiment had two treatments: a) Soil without fertilization the first year and b) Fertilization according to soil chemical analysis. The second year all plots received the same fertilizer formula through the irrigation system. The experimental design was a randomized complete block with 4 replications. No differences (P≤0.05) were observed in total and marketable strawberry yield during the first (2003/04) and the second (2004/05) harvest season between both treatments. Among all evaluated parameters - total and marketable yield, fruit size and weight, percentage of rejected fruits and its causes, and fruit soluble solids content (°Brix) - only the percentage of rejected fruits in the first harvest season was different between treatments, being higher (P≤0.05) in the fertilized plots than in the unfertilized ones. Results of foliar analysis of the unfertilized plants, taken at the end of spring in the first harvest season, showed normal levels for P, K, Ca, Mg, Fe, Cu, Mn, and B, and a little below than critical levels for N and Zn. Nevertheless, deficiency foliar symptoms were not observed.